Audio Research D115 Power Amplifier

Here we have a classic power amplifier from American company Audio Research. The D-115 was originally introduced in 1983 as the more powerful option in a two model range and our example does show some signs of its age, however it is in fully working condition and comes professionally packaged. It is also supplied with the original manual and our regular three month warranty.
Audio Research Said….
Audio Research introduces the D-115, conceived in response to the need for totally accurate music reproduction. It is doubtful that any amplifier, regardless of cost, can exceed the D-115 in value or overall performance.
The D-115 relies on straightforward design approaches and incorporate patented Audio Research cross-coupled circuitry. To this topology a number of significant improvements in power amplifier technology have been added, a few of which are proprietary.
Wide band, ultra-stiff, fully regulated power supplies have been combined with Audio Research patented and fully balanced output circuitry, creating highly stable amplifiers capable of providing highest performance levels into even the most difficult loads. Proprietary circuitry minimizes distortion and provides a more accurate interface with low level stages and driver circuits. Extensive research into transformer technology has created more efficient and more tightly coupled output transformers. Consistent with Audio Research methodology, the D-115 uses only the finest materials in its construction.
The result of this attention to all parameters of amplifier design are increased detailing, wider bandwidth, significantly reduced distortion, improved low frequency accuracy and an amazingly accurate and realistic presentation of voices and instruments, even during complex and highly dynamic material. D-115 is capable of state-of-the-art performance.
Features:
Patented Audio Research cross-coupled and fully balanced circuitry.
Front panel power switch, relay coupled for smooth and reliable turn-on.
Front panel LED indicators for line and screen.
Front panel fusing for line and screen.
Sonically selected components for optimum sound performance.
Near military grade construction used throughout.
Specifications:
Power Output: 100 watts per channel minimum continuous power at 16 ohms from 20 Hz to 20 kHz with less than 1% total harmonic distortion
Power Bandwidth: (-3dB points) 10 Hz to 60 kHz.
Input Sensitivity: 1.2 V RMS for rated output
Input Impedance: 75K ohms, nominal
Output Regulation: Approximately 0.4 dB, 16 ohm load to open circuit
Overall Negative Feedback: 20 dB
Damping factor: Approximately 20
Intermodulation Distortion: Less than 0.1 % at 1 dB below rated output
Slew Rate: 15 V/µs
Rise Time: 5 µs
Hum & Noise: 90 dB below rated output – less than 2mV RMS
Power Requirements: 105 – 125 VAC 60 Hz (210 – 250 VAC 50 Hz) 1000 watts maximum, 400 watts at “idle”
Tube Complement: (4 matched pairs) KT77, (1) 6550, (1) 12AT7, (7) 6DJ8/ECC88.
Dimensions: 480 (W) x 420 (D) x 180 (H) mm
Weight: 31.0 kg